Automatic electric switch



July 24, 1928.

R. PENN AUTOMATIC ELECTRIC SWITC Filed April 24, 1925 Patented' `luly 24, 1928i.

UNITED STATES PATENT OFFICE.

RALPH PENN, OF DES MOINES, IOWA, ASSIGNOR TO PENN ELECTRIC SWITCH COH- PANY, A. COPARTNEBSHIP COMPOSED RALPH PENN, AND BLANCHE G. PENN.

PENN, MARY S. PENN, ALBERT AUTOMATIC ELECTRIC SWITCH.

yApplication led April 24, 1925. Serial No. 25,519.

My invention relates to that class of electric switches intended to be operated by fluid pressure, ioats or the like.

It is my purpose to provide a switch of this kind of simple, durable and inexpensive construction.

Another. object of my invention is to rovide a switch of the kind mentioned, W ich will operate accurately and dependably under all circumstances.

Still another purpose is to provide such a switch having certain novel lfeatures of construction, which insure as nearly as possible the instantaneous opening of the switch.

This purpose is accomplished by providing an actuating device having two members with a spring arranged between them, the two members being pivoted at points so separated that in their actuation, the spring is never on dead center with relation to both j pivot points at once, whereby there is accomplished the desirable result of swinging one member past dead center so that the spring tends to give it speeded-up movement before the spring passes over dead center with relation to the other member, whereupon when the spring does pass over dead center'withI relation to the other pivot, it will do so with a very quick movement for thus insuring an instantaneous opening movement of the movable contact member. t

Another purpose of my device is to provide a switch of the .type under consideration having parts so constructed and arranged that the entire device is very compact so that it will occupy a. relatively small s ace.

pVVitl. these and other objects in view, my

invention consists in the construction, arrangement and combination of the various parts of my automatic electric switch, whereby tle objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 shows an elevation of a switch embodying my invention, parts being broken 'away and par-ts being shown in section.

Figure 2 shows a sectional view .taken on the line of Figure 1, illustrating the switch structure as viewed from the under side thereof.

Figure 3 is' a view similar to that shown in Figure 1, illustrating the parts in a position different from that'shown in Figure 1; and Flgure 4 is a diagram illustrating the operatlonof my improved switch.

In the accompanying drawings, `the nu- `meral 10 has been used to indicate generally a suitable case for the switch.

In t-he case, there is arranged a lever 11 mounted by means of a pivot pin 12 on the case 10. The lever 11 forms an actuating member'for the movable switch contact.

Qne end of the lever 11 projects through a suitable slot or opening 13 in the case 10 and 1s designed to be connected for. instance with a float or other outside actuating means.

The other end of the lever 11 forms a U- shaped yoke 11. The wall of the case 10 at theopposite ends of the slot 13 serves .to limit the pivotal movement of the lever.

rI he fixed contact member, I will now descrlbe. It may be said in this connection that the contact member may be of any suitable form. It is mounted on a bracket which 1s herein described in some detail, because I believe there are certain novel features of .structure about the bracket and the manner 1n which it supports parts of the device. However, the bracket might be made in various forms and still come within the spirit of the principal feature of my invention.

This bracket comprises a plate 14 su ported rigidly as for example at 15 on t e wall of the case 10 and projecting therefrom. Contact points' 16 are mounted on the plate 14 and project therethrough, insulated therefrom in any suitable"manner.

Connected with the contact electric wires 17.

The plate 14 has at one end a projection 18 narrower than the plate, provided in the form of the device here shown 4with spaced downwardly projecting ears 19. These ears have at their lower ends, .tongues 20 which are inclined toward each other as shown in Figures .1, 2 and 3.

The opposite side edges of these tongues form pivots for the members of the actuated device hereinafter described.

The actuated device comprises two members, indicated generally at 21 and 22. These are channel-shaped members. The walls 21a and 22"i of the members21-and 22 have suitable notches 23 and 24 shown for instance in Figure 3, which engage the opposite edges of the tongues 20 as pivots.

points 16 are Formed on the members 21 and 22 are tongues 25 and 26 to which a spring 27 is connected under tension for thus holding the members 2l and 22 against the edges of the tongues 20.

It will be noted that the arrangement of the tongues is such that they are inclined in such a way that the spring 27 in passing over the pivots of the respective members 21 and 22 pass over dead center with relation to one pivot at a diil'erent position in its movement than it reaches in passing over dead center with relation to the other pivot.

The pivots might, of course, be in any form, but this arrangement whereby the spring never in the actuation of the device reaches dead center with relation to both pivots at the saine time is an important feature of my invention.

A link 28 is pivoted to the member 22 at a point between its pivot and the tongue .26. The link 28 has an elongated hole 29 receiving a pivot pin 30 on the lever 11, in such manner as to allow lost motion between the lever 11 and the link 28.

At one end of the member 22 beyond the tongue from the pivot tonguesI 20 is a short extension 31 fixed to a bar 32 of insulating material. Supported on the bar 22 at opposite ends thereof are leaf spring metal contact members 33, which are connectcd with conducting wires 35.

In the practical operation of a switch of this type which is actuated from a ioat or pressure tank, there is always involved the roblem of separating the movable from the Excel contact without drag, which produces arcing and causes the parts to be burnt out.

The device here shown insures a quick separating movement.

In the practical operation, assuming the parts to be in the position shown in Figure 3, then as the left-hand end of the lever 11 is moved upwardly for lowering the link 28 and the member 22 of the actuated device, it will be seen that the right-hand end of the spring 27 will be gradually moved downwardly until the spring reaches dead Acenter with relation to the pivot of the member 22.

During this movement, the pin or pivot is in the lower part of the slot 29.

After the spring passes over center with relation to the pivot of the member 22, it tends to quicken the downward movement of the member 1() with an accelerated movement, which I call the.` speederator movement.

The first downward movement of the member 22 is slow for the reason that tlie actuating movement of the lever 11 is ordinarily .very slow.

The speeded-up movement of the member 22 after the spring passes over dead center with relation to the pivot of the member 22 is not interfered with by the lever 11, be-

cause of the 10st motion connection of the link 28 therewith.

During the speeded-up movement of the member 22, the link 28 moves downwardly faster than the right-hand end of the member l1. This relative movement of the link 28 with relation to the member 11 is made possible by the use of the elongated slot 29.

During this speeded-up movement of the member 22, the spring 27 vpasses dead center with relation to the pivot of the member 2l with a rapid movement.

As soon as the spring 27 does pass its lastnamed dead center position, it jerks the member 21 downwardly with a very quick movement for thus almost instantaneously separating the contact points.

This is a feature of very great importance in a switch of this kind because it prevents arcing.

In Figure 4, I have shown a diagram illustrating the position of the parts during the operation of the device. The dotted line A indicates the position of the spring 27 when the switch is closed. The line B indicates the position of the member 22, and the line C the position of the member 21 in the closed position of the switch.

When the switch is operated for breaking the connection, the member 22 moves down to position where the spring is on dead center with relation to the pivot point D of the member 22, as indicated by the line E.

The spring then passes over the dead center D and then tends to accelerate the movement of the member 22. The movement of the member 22 is continued until it reaches the position indicated by the line F at which time the spring is in the position indicated by the line G onidead center with relation to the .pivot H ofthe member C.

0n account of the accelerated movement of the member 22, the spring passes this position with a rapid movement and pulls the member C with a quick movement to its position indicated by the line I, the spring passing down to the position indicated by the line J. The member 22 then occupies the position indicated by the line K.

On the return or closing movement of the switch, it is not so important that the beginning movement of the movable contact be quick, but it is important that the final closing movement be quick. This, however, is not such a difficult problem to solve.

In the closing movement, the lever 11 moves the member 22 upwardly from its position indicated by the line K to its position indicated by the line L at which time the spring reaches the position indicated bthe line M where it is on dead center with relation to the pivot point H.

The further forward movement of the member 22 toward its position indicated by lou the line B carries the spring over center with relation to the pivot H, whereupon the spring starts the member 21 on its upward movement, which continues rapidly and with accelerated speed uri-til the switch is closed.

It will be noted that b the arrangement of the pivots D and H, have providedI a structure which permits the member 22 to attain considerable rapidity of movement during the opening actuation of the switch before the spring passes center with relation to the pivot H, and then begins k,to actuate the member 21 for breaking the contact.

As result, the breaking of the contact is accomplished with a very quick movement. This avoids the rather common unsatisfactory feature found to exist in electric switches operated by pressure or by a float. The oat which operates the lever 11 moves comparatively slowly in ordinary practice, so that unless some accelerator or speederator device of the kind herein mentioned is employed, the contact 33 would tend to leave the Contact 16 with a drag.

My device eliminates this tendency.

It will also be noted that the devlce is so constructed that it is very compact and may be mounted in a casing of small size, so that it can be used in places where economy of space is important.

The parts employed are relatively few and simple and inexpensive.

It is obvious that changes may be made in the details of the structure of the device Without departing from the real spirit and purpose of my invention, and it is my intention to cover by the claims of the patent to be issued upon my application any modified forms ot structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a device of the class, described, a support, a bracket mounted thereon having spaced ears formed with opposite inwardly projecting tongues, a pair of channel-shaped members having slots pivotally engaging the opposite sides of the tongues, a sprlng connectcd with said channel-shaped members on opposite sides of the tongues, said tongues being so arranged that the pivot points formed thereby are never simultaneously on dead center with relation to the spring, and means for actuating one of said members on" the pivots.

2. In a structure of the class described, a pair of channel-sha ed members, each rovided in its walls with slots, means received in said slots for forming pivots for the respective channel-sha ed members, a spring connected with sai channel-sha d members on opposite sides of said plvots, said pivots being so spaced that ythey are never simultaneously on dead center with relation to the spring, and means for actuating one of said members.

3. In a device of the class described, a support, a bracket thereon having spaced ears formed with opposite inwardly projecting tongues, a pair of channel-shaped members having slots pivotally engaging the opposite sides of saidtongues, a spring oonnected with said members on opposite sides of the tongues, said tongues being S arranged that the pivot points formed thereby are never simultaneously on dead center with,

relation to the spring, a movable contact supported by one of said members, an actuating member, and a lost motion connection between. the actuating member and the other of said first-described members. g

4. In a device of the class described, a slipport, a bracket thereon havin spaced ears formed with opposite inward y projecting tongues, a pair of channel-shaped members having slots pivotally engaging the op ite sides of said tongues, a spring connecte with said members on opposite sides of the tongues, said tongues ing so arranged that the pivot points formed thereby are never simultaneously on dead center with relation to the spring,` one of said members hav' an extension, an insulating bar supporte by said extension, a member hav' an extension being provided with shoul ers for engaging said bar, a contact member supported by said bar, an actuating member and a lost motion device connecting the actuating member and the other of said first-described members.

Des Moines, Iowa, Februar 1925.

RAL H iENN. 

